as-Sadiq عليه السلام said: Do tasbih thrice in your ruku`, saying: subHaana rabbiya ‘l-`azheemi wa bi-Hamdih, three times, and in the sujud: subHaana rabbiya ‘l-a`laa wa bi-Hamdih, three times, for when Allah عزوجل sent down upon His Prophet صلى الله عليه وآله سلم “So glorify your Lord the Almighty” (56:96), the Prophet صلى الله عليه وآله سلم said: Put it in your ruku`. And when Allah sent down “Glorified be the name of your Lord the Most High” (87:1), he صلى الله عليه وآله سلم said: Put it in your sujud.

فإنقلت: سبحاناللهسبحاناللهسبحانالله،أجزأك .

And if you say: subHaanAllaahi subHaanAllaahi subHaanAllaah, it suffices you.

وتسبيحةواحدةتجزيللمعتل،والمريض،والمستعجل .

And a single tasbiha suffices for the ill (or: one with an excuse), the sick, and the hurried.